Relief valve



Jan. 12, 1937 w. T. BIRCH RELIEF VALVE Filed March 4, 1935 AN QN QQ 4 LII/d Y ///////Y a Patented Jan. l2, 1931 UNITED STATES PATENT OFFICE RELIEF VALVE William T. Brc Chicago, Ill.

Application March 4, 1935, Serial No. 9,313`

claims. (ci. 137-53) The present invention relates to fluid pressure regulators and more particularly to relief valves, such as are used in conjunction with pressure regulators in closed hot water heating systems.

5 By the use of such regulators and relief valves a constant pressure is maintained in the system below that of the supply pressure, the relief valves opening the outlet pressure to the atmosphere whenever expansion of the water, due to high temperature in the system, increases pressure therein above the safety or set point. After the water in the system cools so that the pressure falls below the s'et point, the main or regulator valve permits the inow of supply pressure so as to raise the pressure in the system to the set point.

It is customary to provide means whereby the relief valve may be adjusted to open at a pressure determined by the condition of the equipment of the heating system, and the desired operating 20 temperature. Such adjusting means are, unfortunately, usually accessible to persons who may adjust the valve to obtain. a desired operating temperature without regard to the condition of the heating equipment, and failures of the equipment, with great injury to persons and to property, have heretofore been all too frequent.

It is an object of the present invention to provide means whereby the valve may be adjusted within safe operating limits.

It is a further and important object of th present invention to provide means whereby any attempt to adjust the valve for other than a safe operating pressure is thwarted.

Other and further objects of the present invention will appear hereinafter.

In the accompanying drawing:

The ligure is a central vertical longitudinal section through the complete unit, with parts in plan.

The regulator and relief valve unit has a casing indicated generally at I Il. At one end, the casing I0 is provided with a water inlet II, into which a service pipe is connected in use, and at the other end there is an outlet I2 for connection so as to be removable from below and to normally present a downwardly directed valve seat for engagement by a regulating valve I9.

In vertical alignment with the port I6, the base of the casing l0 has an opening normally closed by a screw ca'p 20 adapted to support the lower end of a cylindrical screen 2I which extends between the web Il and the cap.r

The valve I9 is inserted in a recess formed in a valve-carrying member 22 which is threaded on a valve stem 23,' and the carrying member is provided with a downwardly extending annular wall portion 24 which encircles an upstanding annular wall 25-formed on the vscrew cap 20 to provide a dash pot 26 for the valve assembly. The carrying member 22 is suitably held in position as by al nut 21 threaded on the stem 23. v

The wall -25 is adapted to function as a guide for the carrying member 22 and the valve I9 so that they may move in guided alinement with the port I6, and suiicient clearance is provided between the walls 24 and 25 to permit free relative movement of the opposed walls. 'I'he wall 24 gives substantial protection to the wall 25 against the accumulation of whatever foreign matter may escape through the screen 2l, and also guards against the passage of foreign matter into the dash pot 26.

'I'he stem 23 extends vertically through the port I6, and the upper end of the stem is enlarged at 28 to provide a large bearing area, and is continued in a reduced section to its end where a nut or washer 29 is threaded on, and this washer is provided with a beveled edge 30'. Disposed opposite, the washer 29 is a washer 3l seated on the enlarged portion 28 o f the stem, and between these washers is clamped a diaphragm 32, formed of a pair of dished members, and which are seated on the casing I9 and held in position by a hood 33 screwed into position to engage the marginal portions of the diaphragms.

'I'he washer 3| is also provided with a beveled edge to provide a curved face or fulcrum for the diaphragm as it exes in operating the valve.

A cap 34, of soft rubber,or the like, is tted over the threaded washer 29 to provide al seat 4for the lower end of a coiled compression spring 35, housed in the hood 33.

An adjusting screw 36 is threaded through the head of the hood 33, and bears against apressure plate 31 provided 'with a lower vportion reduced to enter the spring 35, and a cap 38, of soft rubber, or the like, is'interposed between the pressure plate andv the spring.

The web I1 is also bored to provide a port 39 communicating with the channel I5, and in this port a valve seat member 40 is threaded so as to be removable from below, and to normally present a downwardly directed valve seat for engagement by a primary check valve 4 I. The valve 4I is seated ina recess in a member 42, and the member 42 is pressed upwardly by a coiled spring 43 seated in the inner face of a dished screw cap 44 threaded into-a bore in the casing I0.

The member 42 is provided with an integrally formed and downwardly extending annular wall 45-which enters the coiled spring 43, and is guided in its movementl by an upwardly extending guide member 46 formed on the cap 44 and enteringthe lower end of the cup dened by the wall. 'I'he clearance between the inner face of the wall 45 and the guide member 46 is enough to permit free relative movement of these parts while they function to provide a dash pot for the valve assembly. The member 42 is also guided in its movement by inwardly extending and peripherally spaced ribs 46 formed integral with the annular wall of the plug 44.

A secondary check valve 4l is placed in 'the chamber I4 to prevent return flow through the channel I5, and this valve seats on an upwardly presented valve seat 48 formed in the chamber Ill. The valve 4l is secured to one end of a flat spring arm 49 which is curved and is anchored at its other end to a boss 50 upstanding from the base of the outlet chamber I4.

The valve 4l is normally pressed against the seat 48, and it will be obvious that it provides means to prevent return now of fluid from the heating system while the primary check valve 4I is removed for inspection or repair.

The outlet chamber I6 is closed on one side by a diaphragm 5I, formed of a pair of dished members, and the diaphragm 5I is seated at its peripheral portion on the casing I and is held in place by a hood 52 threaded in the casing.

An inverted cup-shaped member 53 is provided with an upwardly extending reduced portion which extends through a central aperture in the diaphragm i, vand the diaphragm is clamped between the member 53 and a nut 54 threaded on the upper end of the reduced portion.

A'hexagonal plug 55 has an upwardly extend' ing reduced portion threaded in the reduced portion of the member 53 and a primary valve 156 1s entered in a recessformed in the lower end of the plug. The valve 56 normally engages a valve seat member 5l' threaded in a bore of the casing Ill, and the member 5l is provided with a central bore 58 forming a port for the discharge of iiuid when the valve 56 lifts as the diaphragm 5I is flexed upwardly by an excessive pressure in the heating system. The bore in which the member 5-'I is entered is large enough to permit the with-l drawal therethrough of the plug 55 for`renewal` or inspection of the valve 56.

The lower edge of the annular wall of the member 53 is recessed, and a secondary annular valve 59 is entered in the recess to cooperate with an alined and annular boss 60, formed on the casing Ill, to close the port 58 in the event that the primary valve 56 or the member 51 are withdrawn for inspection, or that the valvev 56 becomes bad- 1y worn. v

The valve seat member 51 extends inwardly into the chamber I4 so that its inner end provides a seat disposed in a plane above that of the seat provided by the boss 60 and so that the' secondary Valve 59 is held inspaced relation to its seat 60 when the primary valve 56 is in goo'd condition. The inner end of the member 51 is tapered, and the normal clearance between the secondary valve 59 and its seat 60 is adjusted to permit the free flow of fluid to the port 58 when the primary valve 56 .functions to release fluid from the system.

It will now be apparent that the primary valve 56 may be renewed while the heating system is in service, and that the secondary Valve 59 automatically closes the port 58 when the member 5l is unscrewed or the primary valve becomes badly worn, provided, of course, that the system pressure is not excessive.

The hood 52 is openat its upper end, and is provided with a cap 6I which is threaded thereon. An adjusting screw 62 is threaded in the cap 6I to bear against the central portionA of a pressure plate 63 and compress a coiled spring 64 seated at its lower end on a cap 65, of soft rubber or the like, placed on the nut 54. A cap 66, of soft rubber, or the like, is interposed between the pressure plate 63 and the spring 64.

The diameter of the pressure plate 63 is greater than that of the bore of the hood 52 at its upper end, and the upper end of the hood presents a ledge or seat B'I to limit downward travel of the plate. The plate 63 is reduced in section at its central portion 68, to provide a central recess, and the lower end of the screw 62 is reduced to t in this recess and provide a shoulder 69 adapted to engage the upper face vof the plate 63 should the reduced end of the screw be forced through the plate.

It will now be apparent that should an unauthorized person attempt to set the relief valve for an excessive pressure by screwing down the screw 62, movement of the plate 63 will be arrested by the ledge 67, the square end of the screw will puncture the plate, and the plate will be forced up against the shoulder 69,` thus causing a slight reduction in the pressure of the spring 64 on the diaphragm 5I. The sudden releasing of the plate is enough to inform the tamperer that the end of the screw has been released, but the drop in the system pressure is not enough to seriously interfere with the heating of the home in severe weather. -It is obvious that a ,Y scale forming materials; where the city water pressure may be temporarily lower than the pressure necessary to send hot water to radiators at elevated points; where a city ordinance forbids the placing of a valve between the heating boiler and the relief valve to guard against boiler explosions, and where the city water pressure may vbe unusually high.

'Ihe provision of a dash pot for the valve I9 makes for smooth operation of the valve even when the city pressure is unusually high, and the disposition ofthe elements of the dash pot is such as to', ensure their proper function even when the water is unusually dirty. The elements forming the dash pot prevent swinging of the valve at times of sudden increase in the supply pressure when faucets connected tov the water supply are closed suddenly.

Scale in the hot water chamber of a relief valve interferes with the proper seating of check valves, and if hot water nds its way into the city water system at times of low city pressure and high heating system pressure it makes water meters inoperative and causes a serious operating hazard. The provision of primary and secondary check valves in the device herein described makes possible the frequent inspection of the primary valve without interfering with the operation of the system, and scale in the hot water end of the channel I5 will drop into the cup or sediment chamber of the screw plug 44 where it may be easily removed. Water entering the hot water chamber tends to wash the face of the check valves because water flow is in the direction of valve opening.

The secondary valve 59 provides a cut-olf valve between the boiler and the primary valve 56 in the event that the primary valve becomes defective or is removed for repair, but this cut-off valve is also subject to control by the diaphragm 5I and is therefore subject to operation by the system pressure to prevent boiler explosions. The plug 55 is hexagonal so that it may be readily turned by a tool entered throu'gh the alined bore in the casing, and the lower or exposed endof the member 51 is also suitably shaped to accommodate a wrench. Near its lower end the member 51 is enlarged at 10 to provide a shoulder adapted to' abut the casing and limit inward travel of the member 51. The lower portion of the bore in the casing is enlarged at 1l and threaded to receive the end of discharge pipe 12. The end of the discharge pipe vmay be arranged to abut the shoulder 10 and so provide 'a lock against unscrewing of the member 51.-

I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than is necessitated by the prior art.

What is claimed is:

1. A relief valvevstructure comprising a casing havingan opening closed by a diaphragm, a relief valve secured to said diaphragm, a seat -in said casing for said valve, a hood threaded on said casing and arranged clamping said diaphragm at its peripheral portion, said hood having a cupshaped cap threaded thereon at its upper end, a coiled spring in said hood and seated at one end on said diaphragm, a pressure plate seated on the other end of said spring, said plate having a reduced central portion defining a recess, a screw threaded through the head of said cap, said screw having a reduced and unthreaded end portion entered in said brecess in said plate and bearing against the reduced portion of said plate, said screw being provided with'means defining a shoulder adapted to engage said plate 'when the reduced portion of said plate yields under excessive pressure thereon, and means on said hood defining a shoulder adapted to be engaged by said plate to limit movement of said plate.

2. A relief valve for a hot water heating system comprising a casing formed of a body porpressure plate, a closure member threaded on the upper end of said cap, a screw threaded in said closure member and engaging said pressure plate, said screw having a reduced elongated end portion adapted to pierce and extend through said plate when excessive pressure is applied thereto, and having an enlarged portion providing a shoulder to limit upward movement of the pierced plate.

3. A relief valve for a hot water heating system comprising a casing formed of a body portion and an open-ended cap and having a diaphragm interposed between said body portion and said cap, said body portion having a bore formed extending through a side wall thereof, an inwardly directed annular wall on said body portion and about said bore defining a first valve seat, an inwardly directed annular wall within said rst wall and defining a second valve seat adapted to be withdrawn through said bore, a ported support for said second valve seat removably positioned in said bore, a rstv cup-shaped valve member removably secured to said diaphragm and having a lip adapted to engage said rst valve seat, a second valve member removably secured to said first valve member, and within the cup, adapted to engage said second valve seat and also being adapted to be withdrawn through said bore, a coiled spring in said cap seated at its lower end on said diaphragm, a deformable pressure plate seated on the upper end of said spring, means on said cap to limit downward movement of said plate, a closure member threaded on the upper end of said cap, a screw threaded in said closure member and engaging said pressure plate, said screw having a reduced end portion adapted to pierce said pressure platev when excessive pressure is applied thereto and having an enlarged portion above said reduced portion providing a shoulder to limit upward movement of the pierced plate.

4. A relief valve for a hot water heating system comprising a casing having means' defining a conduit therethrough provided with an inlet and an outlet, and having a side bore extending through a wall thereof to provide a relief outlet in communication with said conduit, a diaphragm in said casing movable responsive to the pressure of water in said conduit, a first valve seat member removably secured in said bore and provided with a port, an inwardly directed annular wall formed integral with said casing and about said bore defining a second valve'seat, an inverted cup-shaped valve member having a reduced extending `portion extending upwardly through said 'diaphragm and secured thereto, and having a depending annular wall disposed in opposed spaced relation to said second valve seat, said annular wall being recessed and tted with a packing in said recess cooperable with said secondvalve seat, and a plug threaded into said extending portion of said cup-shaped member, said plug being recessed and fitted with a packing in said recess cooperable with said first valve seat, said plug being normally in engagement with said rst valve seat and said cup-shaped valve being normally out of engagement with said second valve seat.

5. A relief valve for a hot water heating system comprising a casing formed of a body portion and an open-ended cap and having a diaphragm interposed between said body portion and said cap to dene a water chamber, said body portion being provided with an inlet and having a bore formed through a side wall thereto said diaphragm, said second valve being arof to provide a relief port, a ported member removably entered in said relief port and providing a rst Valve seat, a rst valve removably secured to said diaphragm and lmovable therewith to engage saidiirst valve seat to close said relief port, a compression spring in said cap engaging said diaphragm to normally maintain said first valve in closing position when the systempressure is normal, means defining a second valve seat in said casing, a second valve secured through said relief port for renewal Without disturbing the assembled relation of said diaphragm -and spring with said casing while the system is under pressure and without depriving the system of relief valve protection. l

WILLIAM T. BIRCH. 

